The present disclosure is related to display devices, and more specifically to a card or the like employing a piezoelectric charge generator for temporarily driving a display.
There are today a relatively large number of different techniques for producing electronic devices. One family of such techniques, of interest herein, is commonly referred to as printed electronics processes, and the resulting devices referred to as printed electronics. Various methods fall within the definition of printed electronics processes. Screen printing, traditional and digital lithography, flexography, gravure and jet-printing are a number of the more common of such methods. In each case, a conductive, semi-conductive or insulating material is deposited over a substrate to form interconnected passive and and/or active electronic components. Printing processes typically deposit materials in the form of a solution, a slurry or a powder. Transfer processes such as thermal transfer or laser transfer processes may also be used to print structures. In a thermal transfer process, a layer such as a metal film may be transferred from a carrier substrate to another substrate. Known printed electronic processes can utilize a wide variety of materials for these components, and are not limited to organic materials.
Printed electronics processes enable the integration of electronic, optical, and other functionalities into products at potentially ultra-low cost. Printed electronic processes take advantage of known, relatively simple printing techniques, and are thus typically less expensive and often less environmentally hazardous than traditional lithography and deposition techniques. Certain materials and techniques used for printed electronics processes permit printing on non-crystalline substrates, such as paper, plastic, fabric, etc. Such processes may permit printing on flexible substrates, which is not easily done with conventional electronic device fabrication techniques. Furthermore, printing processes have been developed for non-planar surfaces, which is also a challenge for conventional electronic device fabrication techniques. However, in order to maintain low cost and/or substrate flexibility, the components produced by printed electronic processes are relatively large, the circuits are relatively simple, and the circuits are fixed in terms of circuit layout and characteristics once produced.
“Printed” batteries are often provided in order to provide power to associated printed electronic circuits. However, printed batteries have several disadvantages. Batteries employ electrolytes that make fabrication (particular with respect to sealing or encapsulation) relatively complex. Moreover, batteries lose charge over time. Batteries of sufficient charge often have a relatively large form factor, incompatible with ultra-compact or ultra-thin devices. Printed batteries may also significantly add to the cost of producing a printed electronics device.
Accordingly, there is a need for a printed electronics device with an improved power source. The power source preferably is relatively simply in design, relatively inexpensive to manufacture, may be manufactured by methods compatible with otherwise known printed electronic devices, does not suffer from loss of charge over time, and may be relatively very compact and/or thin.